Mechanism for ejecting workpieces from a die

ABSTRACT

A KNOCKOUT MECHANISM FOR EJECTING WORKPIECES FROM A DIE WHICH COMPRISES A KNOCKOUT PIN SLIDABLY MOUNTED IN THE DIE AND SLIDABLY SUPPORTED IN A BORE IN THE FRAME THEREFOR, THE KNOCKOUT PIN COOPERATING WITH A SLEEVE MEMBER HAVING AT LEAST ONE ARM PIVOTALLY MOUNTED THERE-   ON AND COOPERATING WITH A FLANGE ON THE END OF THE FORWARD SECTION OF THE PIN SUCH THAT THE END OF THE ARM CAN PASS OVER AND GRIP THE FLANGE IN ORDER THAT THE SLEEVE MEMBER BE SLIDABLY RETRACTED WITH SAID KNOCKOUT PIN.

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Filedl April 22, 1969 De D (m9 ,MATT RNEYS 17 1 NNN E N MECHANISM FOREJECTING WORKPIECES FROM A DIE ww 911m Sept. zo, 1911 United StatesPatent 3,605,499 MECHANISM FOR EJECTING WORKPIECES FROM A DIE Anthony M.Putetti, Waterbury, Conn., assignor to Textron, Inc., Providence, R.I.Filed Apr. 22, 1969, Ser. No. 818,303 Int. Cl. B21d 45/00 U.S. Cl.72-345 8 Claims ABSTRACT F THE DISCLOSURE A knockout mechanism forejecting workpieces from a die which comprises a knockout pin slidablymounted in the die and slidably supported in a bore in the frametherefor, the knockout pin cooperating with a sleeve member having atleast one arm pivotally mounted thereon and cooperating with a flange onthe end of the forward section of the pin such that the end of the armcan pass over and grip the flange in order that the sleeve member beslidably retracted with said knockout pin.

This invention relates to a knockout mechanism for ejecting workpiecesfrom a die and more particularly to a mechanism for ejecting blankshaving relatively long shanks from a heading die.

Conventional knockout mechanisms for use in heading and extrudingmachines generally comprise a knockout pin acted upon by a knockout rod.The knockout pin is adapted to travel through a die so as to displacethe shank of a formed workpiece therein. The knockout pin has a portionof larger diameter which is acted upon by the knockout rod in timedrelation to the formation of the workpiece. When a punch is retractedafter a forming blow on a workpiece in the die, the knockout rod isactuated by a connecting lever assembly so as to drive the knockout pinthrough the die, thus removing the formed workpiece therefrom. Theknockout pin and knockout rod are then returned to their originalpositions by means of another workpiece being inserted into the die orby biasing means adapted to return the knockout pin and knockout rodafter clearing the workpiece from the die.

A conventional knockout mechanism such as described above is fully setforth in U.S. Pat. No. 3,328,761. Such a conventional knockout mechanismperforms satisfactorily in most applications, but difficulties Ihavebeen encountered when the shank of a workpiece is relatively long. Thereason for this is that the section of the knockout pin passing throughthe die must also have a relatively long length in order to clear thedie. Thus, when the relatively small-diameter section of the knockoutpin is located in the bore of the frame, it is supported only at itsends when it receives the force of the pivoting lever. As a result ofthe sudden application of force, the forward section of the pin has atendency to buckle and break, thereby jamming t-he machine and causingother consequential damage.

In view of the foregoing, it is an object of this invention to provide anew and improved knockout mechanism for ejecting workpieces having longshanks from a die.

Another object of the invention is to provide a new, improved,inexpensive and simple knockout mechanism for ejecting workpieces havinglong Shanks.

A further object of the invention is to provide a new, improved andeffective support for a knockout pin in a knockout mechanism for a dieso lthat the knockout pin will not buckle.

Still other objects and advantages of the invention will in part beobvious and will in part appear hereinafter.

Briefly stated, in one form thereof, this invention comprises a knockoutpin having a long, small-diameter for ward section which passes throughthe die to eject a work piece therefrom. Formed integrally with theforward section of the knockout pin is a large-diameter plunger sectionwhich travels in first and second bores adjacent the die in the frame ofthe machine. Located in the first bore is a sleeve having at least onearm: pivotally mounted thereon, which arm is resiliently biased towardthe forward section of the 'knockout pin. A flange is positioned on theforward section of the pin adjacent the plunger section and abuts thearm to move the sleeve as the knockout pin moves through the die. Whenthe pin is retracted, the arm engages the flange on the pin and thesleeve is retracted by the pin. A shoulder at the end of the iirst boreallows the arm to disengage from said tlange. A knockout rod is slidablymounted in the second bore so that it may be acted upon by a lever tocooperate with the pin in a conventional manner.

The invention accordingly comprises the features of construction,combination of elements and arrangement of parts which will beexemplified in the construction hereinafter set forth and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference is had to thefollowing description, taken in conjunction withthe accompanying drawings, in which FIG. l is a partial sectional viewof a heading machine containing the knockout mechanism, showing theknockout pin as it is clearing the die;

FIG. 2 is an enlarged sectional view of a portion of the heading machineof FIG. 1, with the knockout pin in its fully retracted position;

FIG. 3 is an enlarged sectional view of a portion of FIG. 2, showing thesupport means for the knockout pin as it is being acted upon by theknockout rod;

FIG. 4 is a sectional view similar to FIG. 3, showing the arms on thesupport means for the knockout pin engaging a flange on the knockout pinso that the support means may be retracted;

FIG. 5 is a partial sectional View similar to FIGS. 3 and 4, showing thesupport means for the knockout pin as it is returning to its initialposition; and

FIG. 6 is a sectional view taken along line 6---6` of FIG. 5.

There is illustrated in FIG. l a part of a heading machine in which theknockout mechanism of this invention can be used. Although shown with aheading machine, it should be understood that this invention can be usedwith any machine in which it is required to clear a die of long-shankedworkpieces.

Positioned in frame 10 of a machine, such as a header or the like, is abearing surface 11 on which a gate 12 reciprocates. Mounted at the endof gate 12 is a punch holder 13 which carries a punch 14. The punch 14is positioned to operate on a workpiece 1S located in a die 16 so as toform a head thereon. The gate 12 is reciprocated by means of a pitman 17pivotally connected thereto. The pitman 17 rides on a crank 18 of acrankshaft 19, the crankshaft 19 reciprocates gate 12 and causes punch14 to act upon the workpiece.

A workpiece is transferred to the die 16 by transfer mechanism generallyindicated at 20. Such transfer mechanisms need not be explained indetail since they are well known in the art and, in structure, do notform a part of this invention. The die 16 is positioned in frame 10 bymeans of a sleeve 21. Located in back of and supporting the die 16 arebacking plates 22 and 23 having bores 24 and 25 therein to allow for thepassage of a knockout pin 26. Adjacent to and cooperating with pin 26 isa knockout rod 27 which rides in a bore 28 in the frame of the machine.The rod 27 is forced forward by the action of a lever 29 pivotallyconnected to the frame of the machine by a pin 30. The lever 29 ispivoted about the pin 30l by a connecting rod 31, so that the head ofthe lever 29 abuts a stop 32 in its retracted position. The stop 324 isthreadably engaged in a plate 33 so that it can be adjusted for controlof the travel of lever 29. Further, the lever 29 is acted upon by a setof levers and connecting mechanism (not shown), so that knockout pin 26will be forced through the die 16 when gate 12 is in a retractedposition. These other levers and connecting mechanism are disclosed inU.S. Pat. No. 3,238,761.

After a finished workpiece has been ejected from the die, a newworkpiece is brought before the die by the transfer mechanism 20. As thegate 12 moves forward to force the new workpiece into the die, lever 29is pivoted against the stop 32. The workpiece being forced into the diethen returns the knockout pin to its original position, as shownin FIG.2.

Referring now to FIGS. 2-6, it can be seen that the knockout pincomprises a long, small-diameter forward section 34 having substantiallythe diameter of the Workpiece so that it can pass through bore 24.lFormed on the section 34 is a large-diameter plunger section 35 whichslides in bores 25 and 28 formed in the bearing surfaces in the frame ofthe machine. A flange 35a is formed on forward section 34 adjacentplunger section 35. Bore 2-5 extends through the backing plate 23 into abearing surface in the frame of the machine. Support means 36 closelylits in bore 25 and can easily slide therethrough. Adjacent the bore 25,there is formed in the bearing surfaces bore 28 having a smallerdiameter than bore 25 so as to deilne a shoulder 38 which limits themovement of support means 36. The shoulder 38 is formed at a position inthe bearing surfaces such that when pin 26 is in the fully retractedposition shown in FIG. 2, the support means 36 will abut the shoulderand substantially support the central part of the forward section 34 ofpin 26. This positioning of the support means effectively prevents theforward section of pin 26 from buckling when acted upon by lever 29through knockout rod 27. The bores 25 and 28 may be formed in a singlebearing surface or in a number of bearing surfaces. The plunger section35 closely ts in bore 28 and slides therein. The bore 28 extends throughthe frame of the machine so that rod 27 can slide therethrough andcooperate with the plunger section of the pin 26. The knockout rod 27 ispreferably of the same diameter as the plunger section of the pin,although it may be of a somewhat larger or smaller diameter. If thediameters of plunger section 35 and rod 27 differ, the diameter of bore28 will have to be adjusted to enable both of these parts to slidetherethrough.

The support means 36 comprises a sleeve member 39 which tits closelyabout the forward section 34 of the pin to provide good support theretowhile permitting relative movement between the section 34 and sleevemember 39. The sleeve member 39 has two longitudinal grooves 40 and v41therein, substantially diagonally opposite each other, in which two arms42 and 43` are pivotally mounted by means of pins 44 and 45,respectively. In the support means of this invention there need be onlyone arm. However, it is preferred to have two arms substantiallyopposite each other so that the ends thereof can more positively gripilange 35a. Further, more than two arms arranged in similar longitudinalgrooves, may be used with the support means. Projections 42a and 43a areformed at the ends of the arms to permit the arms to grip flange 35a. Itshould be understood that these projections are not necessary since thearms may be curved toward each other in a manner whereby the use ofprojections would not be necessary.

The arms are biased toward each other by means of two O-rings 46 and 47constructed of resilient material such as rubber or a plastic. Althoughit is possible to use only one O-ring, two such rings are preferred, inorder to bias the arms tightly toward each other to llrmly grip flange35a. The O-rings 46 and 47 are positioned in circumferential grooves 48and 49, respectively, in the sleeve so that they will not interfere withthe travel of the sleeve. Any other type of resilient means may be usedto bias the arms toward each other, such as a spring in the form of anO-ring, if such means do not interfere with the movement of the sleevein the bore 25.

In operation, as the lever 29` moves in the direction of the arrow '50,FIG. 2, it will force the rod 27 and the pin 26- to the left, as shownin FIG. 3. As soon as the ilange 35a abuts the projections 42a and 43aat the ends of arms 42 and 43, respectively, the sleeve member 39 willbe forced forward, as shown in FIG. 3.

When the sleeve 39 reaches the end of bore 25 and abuts the backingplate 22, the pin 26 will continue to move forward under pressure fromrod 27, such that the llange 35a passes by the projections 42a and 43a,as illustrated in FIG. l. When a new workpiece is inserted into the die,the pin 26 will be forced backward, carrying sleeve 39 with it since theprojections 42a and 43a will tightly grip flange 35a, as shown in FIG.5. When the sleeve member 39 reaches shoulder 38, it will be unable tomove further. However, the pin 26 will continue to be forced backward bythe workpiece. This results in the opening of arms 42 and 43 to releasethe flange 35a and pin 26 will continue to move until it is in theposition illustrated in FIG. 2. The knockout cycle will then berepeated.

The resiliently-biased arms 42 and 43 provide a simple mechanism forreturning the sleeve member 39 to its initial position, Anotheradvantage of the arms 42` and 43 is that the sleeve member 39 supportsthe forward section of the pin adjacent the plunger section as itreturns to its initial position. Since the plunger section 35 does notlit closely in the bore 25, this support of the sleeve prevents theforward section of the pin from bending due to the weight of the plungersection. Therefore, plunger section 35 of the pin 26 will be alignedwith bore 28 and easily pass into the bore as the pin 26 is retracted.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are etllciently attained andsince certain changes may be made in the above construction withoutdeparting from the spirit and scope of the invention, it is intendedthat all matter contained in the foregoing description and shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

It should also be understood that the following claims are intended tocover all the generic and specillc features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

What I claim is:

1. In a heading machine including a frame, a shaft rotatably mounted insaid frame, means for rotating said shaft, a die bed mounted on theframe, a die mounted on the die bed, a gate reciprocally mounted on saidframe for operation by the shaft, the gate carrying a tool to cooperatewith the die, a knockout pin slidably mounted in the die and in firstand second bores in said frame wherein said first bore lies adjacent tosaid die, a knockout rod slidably mounted in said second bore in saidframe for cooperating with said knockout pin, and a lever pivotallypositioned `on said frame and engaging an end of said knockout rod toadvance said rod against said knockout pin, such that said pin will passthrough the die to clear said die, the improvement comprising a knockoutpin having a long small-diameter forward section and a largediameterplunger section with a flange located on the end of the forward sectionadjacent the plunger section and a sleeve member having at least one armpivotally mounted thereon, said arm extending toward said flange andresiliently biased toward the pin, whereby the end of the arm can passover and grip said flange so that said sleeve member can be slidablyretracted with said knockout pin.

2. In a heading machine according to claim 1, further including at leastone O-ring constructed of resilient material positioned on said sleevemember to resiliently bias the arm toward the pin without interferingwith the travel of said sleeve in said first bore.

3. In a heading machine according to claim 2, a shoulder positionedbetween said rst and second bores in said frame such that the travel ofsaid sleeve is arrested by said shoulder to disengage the arm on saidsleeve from the ange on said knockout pin when said pin is retractedfrom said die.

4. In a heading machine according to claim 1, wherein two arms arepivotally mounted directly opposite to each other on said sleeve memberand extend toward said flange, and wherein said arms are resilientlybiased toward each other.

5. A knockout mechanism for ejecting workpieces having long shanks froma die positioned in a frame by means of a knockout pin acted upon byactuating means, comprising a knockout pin having a long small-diameterforward section and a large-diameter plunger section which is slidablymounted in said die and in first and second bores in said frame, whereinsaid rst bore lies adjacent to said die, a sleeve member closely ttingover the forward section of said knockout pin and capable of movingwithin said rst bore when acted upon by the pin as the pin advances toclear the die, a ange located on the end of the for-ward section of thepin adjacent the plunger section and at least one arm pivotally mountedon said sleeve member extending toward said flange and resilientlybiased toward the pin, whereby said arm can pass over and grip said angeso that said sleeve member can be slidably retracted with said pin.

6. The knockout mechanism of claim 5, wherein at least one O-ringconstructed of resilient material is l0- cated on said sleeve member toresiliently bias the arm toward the pin witohut interfering with thetravel o'f said sleeve in said rst bore.

7. The knockout mechanism of claim 6, wherein a shoulder is positionedbetween said rst and second bores in said frame to arrest the travel ofsaid sleeve member to disengage the arm on said sleeve member from theflange on said knockout pin when said pin is retracted from said die.

8. The knockout mechanism of claim 45, wherein two arms are pivotallymounted on said sleeve member directly opposite each other and extendingtoward the ange, and wherein said arms are resiliently biased towardeach other.

References Cited UNITED STATES PATENTS 1,856,440 5/1932 Spire 7?;-3453,238,761 3/1966 Hoyt M 72-345 3,431,825 3/1969 Crawley 92--165 RICHARDJ. HERBST, Primary Examiner gg C UNITED STATES PATENT OFFICE CERTIFICATE0F CORRECTION Patent No. 3,605 ,N99 Dated September' 2O 1971 iInventor(g) Anthony M Putett It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown beluw:

Column l, line 23 of the specification, change "3,328,761" to 3,238,761.

Claim 6, line U, change "witohut" to w1thout.

Signed und sealed Ehs 18th day of April 1972.

(SEAL) AI test VIT/'HALTE I`-I.FLEI?CIUYTR,JR. ROBERT GOTTSCI-IALK "1tbesgng; Officer Commissioner of' Pa tents

